You do not need to validate your passes. They have already the date of validity on them. All you need to do is have them with you when you board a train (or tram or bus…) and when requested show them to the ticket inspector.
The nicest route to Grindelwald from Zurich would be via Luzern. So just travel Zurich - Luzern - Interlaken - Grindelwald. The direct route is however faster. See www.sbb.ch where you can add a via in order to force a detour.
Your Saver Day Pass will cover you till the Titlis Valley station. You will have to buy a ticket for the Titlis Cable car as it is not included.
Best route you can again find on www.sbb.ch
Tip: The Saver Day Pass is valid on Lake Luzern steamers, and is valid on the Rigi Railways, so maybe make most use of it, and do a nice trip Luzern - Weggis - Rigi and back.